The present invention relates generally to solar collectors, and more particularly to solar collectors that include one or more passive reflective surfaces for efficiently directing incident sunlight into a light pipe.
Conventional skylight systems direct sunlight collected via a structure typically positioned on the roof of a building into the interior of the building, e.g., via a window. Some skylight systems include a light pipe that directs the sunlight collected via its proximal end to a diffuser optically coupled to its distal end. The diffuser can control/shape the pattern of illumination delivered to the interior of the building. Some typical performance metrics of such systems include total lumens delivered by the system (for a given roof-hole diameter), evenness of the daylighting curve, the percentage of the collected light reaching a target surface (known as fitted target efficacy), and the uniformity of target illumination. Some conventional systems employ a tall collector dome with prismatic or Fresnel geometry to re-direct the low-angle sunlight (e.g., early morning or late afternoon) into the light pipe to improve the performance metrics of the system.
There is still, however, a need for improved solar collectors, which can efficiently harness sunlight for lighting applications.